The Nationals rallied against five pitchers in their big burst, winning for just the fourth time in 13 games. The Mets had been off to the best start in franchise history behind the top bullpen in the majors before collapsing.

Trailing 6-1, Washington combined five hits, three walks and a hit batter to go ahead.

Harper's two-run single off Jerry Blevins made it 6-3. Wilmer Difo tied it with a two-out, two-run single off Jeurys Familia, and Michael A. Taylor drew a bases-loaded walk from the Mets closer for a 7-6 lead.

"It was just unfortunate," New York manager Mickey Callaway said. "Off night for a few of them. But we have to move on."

"It's one inning. It wasn't even the game," he said. "We'll learn from it and make sure that it doesn't throw us into some kind of tailspin. Because we're a really good team and we've been showing that."

Harper hit his major league-high eighth home run, and his 33 1/2-inch, 31 1/2-ounce Marucci bat paid the price. It cracked into two pieces, but the ball still flew an estimated 406 feet to right-center field.

The lumber shattered just above his hands, and the barrel helicoptered into the high, protective netting behind home plate on the first base side. The five-time All-Star trotted most of the way to first holding the few inches of the handle that remained after connecting in the first off Jacob deGrom.

On his way back to the dugout, Harper playfully pulled up his sleeve to show his biceps.

The 25-year-old former NL MVP has hit 158 home runs so far. Anything like that?

"Uh, no," Harper said.

Said Martinez: "He started to flex when he came back. I said, `Yeah, you're strong.'"

DeGrom struck out 12 in 7 1/3 innings, the longest outing by a Mets pitcher this season. He left with two on, one out and a five-run lead. He also drove in a run with a safety squeeze.

Washington starter Jeremy Hellickson gave up two runs over 4 2/3 innings in his Nationals debut.

LONG AND SHORT

Cole shifted to a relief role to make room for Hellickson in the rotation. Cole was 0-1 with a 12.00 ERA in two starts this season. The 26-year-old has pitched parts of four seasons for the Nats. Martinez said Cole "fits perfectly" as a long man in the bullpen. "The conversation went really well," Martinez said, adding, "he's all for it."

Along with giving up two runs, Cole threw a fastball that sailed to the backstop and tore a hole in the Dunkin' Donuts sign.

TRAINER'S ROOM

Nationals: 3B Anthony Rendon (bruised left big toe) is still sore after fouling a ball off his foot Friday. ... 2B Daniel Murphy (knee surgery) arrived in Florida and will begin workouts Tuesday at the spring training complex. ... Prized minor league OF Victor Robles won't need surgery after injuring his elbow diving for a ball last week, Martinez said.

Mets: OF Yoenis Cespedes, who played in the Mets' first 14 games, didn't start. The slugger was hitting just .190, striking out 26 times in 58 at-bats. Callaway says Cespedes' timing at the plate is slightly off, and felt a break might help. Cespedes flied out as a pinch hitter. ... OF Jay Bruce (plantar fasciitis) didn't start for the second straight game. He grounded out as a pinch hitter. He hopes to be in the lineup Tuesday.

UP NEXT

Nationals: LHP Gio Gonzalez (1-1, 2.20 ERA) is 10-1 with a 1.69 ERA in 15 career starts at Citi Field.

Mets: RHP Zack Wheeler (1-0, 1.29) pitched seven sharp innings at Miami in his season debut, retiring the last 16 batters he faced. He is 2-7 lifetime vs. Washington - tagged by the Nats in his final two starts in spring training, he got sent to the minors to begin the season.